When run the following script returns an ORA-00936 missing expression error.

select MemNumber,
Turnover
from
(
select mem_number MemNumber,
sum(trans_turnover) Turnover
from members
join transact
on mem_number = trans_code
where Trans_date between '&Start' and '&End'
and mem_barred = 0
group by mem_number
order by turnover desc
)
where rownum <=200
/